This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Anti-Mullerian hormone (AMH), a dimeric glycoprotein from the transforming growth factor ? (TGF-?) family, is specifically produced by granulosa cells of early developing follicles in the ovary and is thought to play an inhibitory role in primordial follicle recruitment. AMH expression is highest in the initial stages of folliculogenesis thus making it an attractive marker for the ovarian reserve (OR). Evaluation of the OR typically occurs in women of reproductive age with subfertility. However, given the high incidence of acquired ovarian insufficiency in girls following chemotherapy or girls predisposed to progressive ovarian failure (i.e. Turner Syndrome, Galactosemia), we propose an early OR assessment in childhood to help monitor and preserve ovarian function. In girls, AMH values are low at birth and rise towards the onset of puberty. This is consistent with the finding that as girls develop from birth to puberty, ovarian size and follicle recruitment increase. Because AMH is closely associated with chronological age and pubertal maturity, age-specific cut-off values are needed to define ovarian insufficiency. In this study, we are recruiting healthy girls, ages 5 to 18 years, living in Harris county to evaluate normal AMH distribution. Subsequent studies comparing AMH levels between at-risk groups and controls will provide new information on the time course and progression of ovarian failure in the study population. Data can then be extrapolated to identify the time period in which individuals may benefit from fertility preserving treatment. Anti-mullerian hormone (AMH) level increases with age and pubertal maturity in girls. This prospective descriptive study will provide data to determine the distribution and variability (standard of deviation) of anti-mullerian hormone (AMH) in healthy girls from childhood to adolescence with respect to pubertal maturation. Ultimately, this data will provide information needed to design future studies on evaluation and management of ovarian health as defined by AMH level in children at-risk for acquired ovarian insufficiency.